Yarn control apparatus and method for circular hosiery knitting machines

ABSTRACT

THE PRESENT YARN CONTROL APPARATUS IS ADAPTED FOR USE WITH CIRCULAR MULTI-FEED HOSIERY KNITTING MACHINES OF THE TYPE HAVING A PAIR OF DIAMETRICALLY OPPOSED YARN CUTTERS AND PNEUMATIC YARN HOLDING MEANS ASSOCIATED WITH EACH CUTTER. THE CONTROL APPARATUS ACTS ON A YARN WITHDRAWN FROM ACTIVE POSITION AT A YARN FEEDING STATION IN ADVANCE OF ONE OF THE CUTTERS FOR PREVENTING ENGAGEMENT OF THIS YARN WITH THIS CUTTER AND FOR DIRECTING THE YARN INTO ENGAGEMENT WITH THE NEXT CUTTER SO THAT THE FREE LEADING END OF THE YARN SEVERED BY THE SECOND CUTTER HAS SUFFICIENT LENGTH THAT IT WILL BE RELIABLY HELD BY THE PNEUMATIC YARN HOLDING MEANS. MECHANICAL CLAMPING MEANS IS ALSO PROVIDED FOR HOLDING A SEVERED ELASTIC YARN UNTIL IT HAS BEEN DRAWN INTO THE PNEUMATIC YARN HOLDING MEANS.

Feb. 6, 1973 YARN CIR

Filed Dec. 28. 1970 CONTROL AP CULAR HOSI lllllllll C. W.M

TON US AND METHOD Y KNITTING MACHIN 2 Sheets-Sheet 1 INVENTOR.

CLARENCE W. M \m'o N Mme/1 MQ Z/W ATTORNEYS Feb. 6, 1973 c. w. MINTON YARN CONTROL APPARATUS AND METHOD FOR CIRCULAR HOSIERY KNITTING MACHINES 2 Sheets-Sheet 2 Filed Dec. 28. 1970 .Ect

w INVENTOR! .z -5 CLARENCETW \\/\\NTON United States Patent US. Cl. 66-140 S 4 Claims ABSTRACT OF THE DISCLOSURE The present yarn control apparatus is adapted for use with circular multi-fecd hosiery knitting machines of the type having a pair of diametrically opposed yarn cutters and pneumatic yarn holding means associated with each cutter. The control apparatus acts on a yarn Withdrawn from active position at a yarn feeding station in advance of one of the cutters for preventing engagement of this yarn with this cutter and for directing the yarn into engagement with the next cutter so that the free leading end of the yarn severed by the second cutter has sufficient length that it will be reliably held by the pneumatic yarn holding means. Mechanical clamping means is also provided for holding a severed elastic yarn until it has been drawn into the pneumatic yarn holding means.

This invention relates generally to a yarn control apparatus and method for circular multi-feed hosiery knitting machines of the type employed for knitting hosiery and the like, and more particularly to a control apparatus and method for use with hosiery knitting machines which include pneumatic means for holding the free leading end of an inactive yarn when it is severed by a cutter positioned closely adjacent the needle circle.

In a single or two-feed circular knitting machine, it is possible to position the pneumatic yarn holding means and the associated cutter a sifiiciently spaced distance from the feeding point of the yarn that the yarns withdrawn from active position are cut a substantial distance from the yarn feeding station. Thus, the yarn has a sufliciently long free leading end to insure that it will be drawn up into and held by the pneumatic yarn holding means. However, many hosiery knitting machines presently in use have eight or more yarn feeding stations so that it is not possible to position the cutters a sufficient distance from every yarn feed that relatively long yarn tails are provided on each of the yarns when they are removed from active knitting position.

Most hosiery knitting machines having eight feeds are provided with two diametrically opposed cutters and a toothed ring which rotates to bring the yarns into engagement with the cutters. The yarns from four of the feeding stations are severed at one cutter While the yarns from the other four stations are severed at the other cutter. As will be appreciated, the yarn withdrawn from action at the yarn feeding station spaced furthest from the cutter will have a relatively long free leading end while those yarns withdrawn from action at the feeding stations positioned progressively closer to the cutter will have shorter free leading ends. The yarn withdrawn from the feed immediately in advance of the cutter thus has a relatively short free leading end which is difficult to engage and hold with the pneumatic holding means. Also, when this yarn feed is utilized to feed an elastic yarn, the elastic yarn immediately contracts When severed and this short leading end is not caught and properly held by the pneumatic holding means. Therefore, the yarn is not properly positioned to be subsequently fed to the needles and the fabric is shed from the needles.

3,714,799 Patented Feb. 6, i973 ice With the foregoing in mind, it is an object of the present invention to provide a yarn control apparatus and method which prevents the engagement of yarns Withdrawn from knitting position closely adjacent to a yarn cutter so that the withdrawn yarn by-passes this cutter and is directed into engagement with the next cutter, thereby insuring that the free leading ends of all yarns withdrawn from active positions pass directly beneath and are of suiiicient length that they will be caught and held by the pneumatic yarn holding means.

In accordance with the present invention, the yarn control apparatus includes flanges extending outwardly from the stationary dial cap and adjacent each of the cutters. Each flange extends over the toothed ring and prevents certain yarns from engaging the rotating toothed ring as soon as they are withdrawn from knitting or active position. Each flange extends for a substantial distance in advance of the corresponding cutter to prevent yarns withdrawn from active position at closely adjacent yarn feeding stations from immediately engaging the toothed ring so that they do not engage the first cutter but by-pass this first cutter and are severed at the other cutter. The present yarn control apparatus also includes mechanical clamping means positioned between the by-passed cutter and the active cutter for holding an elastic yarn which is withdrawn from active position. This clamping means includes a step-down shelf formed on the stationary dial cap with a yarn clamping foot movable into and out of clamping engagement with the shelf for engaging yarns directed to pass over the shelf by the preceding flange.

Other objects and advantages of the present invention will become apparent with reference to the following detailed description of the illustrative examples disclosed in the drawings, in which FIG. 1 is a fragmentary plan view, with parts in section, looking down on the dial and latch ring of a circular eight-feed hosiery knitting machine with the present invention applied thereto;

FIG. 2 is an enlarged fragmentary vertical sectional view taken substantially along the line 2-2 in FIG. 1;

FIG. 3 is an isometric view of the dial of the machine looking inwardly at one of the cutters in the direction of the arrow 3 in FIG. 1;

FIG. 4 is a fragmentary isometric view of the dial looking inwardly in the direction of the arrow 4 in FIG. 1 and with portions of the clamping device broken away for illustrative purposes; and

FIG. 5 is an enlarged fragmentary vertical sectional view taken substantially along the line 55 in FIG. 4.

The eight-feed circular hosiery knitting machine illustrated in the drawings is merely representative of the many different types of multi-feed circular hosiery knitting machines on which the yarn control apparatus of the present invention may be applied. The knitting machine includes a rotating circle of latch needles N which are supported in a conventional manner for vertical movement in a needle cylinder, not shown. A latch ring '10 surrounds the circle of needles N and is provided with a number of yarn feeding stations, depending upon the number of knitting stations in the knitting machine. As illustrated in FIG. 1, the latch ring 10 is provided with eight yarn feeding stations, generally indicated at I through VIII. Each yarn feeding station includes a plurality of yarn feed fingers, such as indicated at 11, 12 and 13, which are conventionally supported for movement between the lowered active yarn feeding position (illustrated by finger 12 in FIG. 2) and the raised inactive position (illustrated by the yarn feed finger 13 in FIG. 2). The yarn feed fingers move between the active and inactive positions to introduce and withdraw yarn from the needles in the conventional manner.

A dial cap or cover 15 is supported inside of the circle of needles N and in a stationary, non-rotating position on a dial cam plate 16. A radially grooved dial bed 17 is supported beneath the cam plate 16 for rotation with the circle of needles N and supports transfer bits 18 for radial movement therein. Suitable cams, not shown, are supported on the dial cam plate 16 for engagement with the upstanding butts of the transfer bits 18 to radially position the transfer bits during operation of the knitting machine in a conventional manner. A toothed ring 20 is mounted beneath the dial cam plate 16 and rotates with the dial bed 17 and the circle of needles N. Saw-tooth shaped teeth are provided on the outer peripheral edge of the ring 20 for engagement with the yarns, in a manner to be presently described.

Suitable pneumatic yarn holding means, such as suction nozzles 21 and 21, are supported in and extend through the dial cap 15 (FIG. The open lower end of each suction nozzle 21, 21' is spaced above the upper surface of the dial cam plate 16 and is adapted to draw any yarn ends upwardly into the nozzle which are disposed in the space above the dial cam plate 16 and below the dial cap 15, in a manner to be presently described. Air pressure lines 22, 22 are directed upwardly in the respective nozzles 21, 21' to create a suction and draw air upwardly into the nozzles 21, 21'. The lower ends of flexible tubes 23, 23' are connected to the upper ends of the nozzles 21, 21' and their opposite ends are connected to suitable yarn end collection chambers, not shown, for collecting any yarn ends drawn upwardly into the nozzles 21, 21'.

Diametrically opposed cutters 25, 25 are supported on the dial cap and positioned in advance of the respective suction nozzles 21, 21. The cutters 25, 25' are identical and each is vertically disposed with a lower sharpened edge which rides upon the outer edge of the toothed ring to cut any yarns brought therebeneath by the toothed ring 20. The cutters 25, are preferably supported in a vertical position in brackets 26, 26' and are normally urged downwardly into engagement with the toothed ring 20 by spring 27, 27' (FIG. 3). Although particular types of cutters 2'5, 25' are illustrated, it is to be understood that other types of cutters may be used. Suitable branch lines 28, 28 extend from the respective air pressure lines 22, 22 and their lower ends are disposed closely adjacent the cutting edges of the cutters 25, 25' to blow away any accumulated lint and the like from the rotating toothed ring 20 as it approaches the cutter.

Normally, the yarns moved between active and inactive positions at four of the knitting stations are cut by one of the cutters, and the yarns moved between active and inactive positions at the other four stations are cut at the other cutter. For example, the yarns at stations I-IV are normally cut by the cutter 25' while the yarns at stations V-VIII are cut by the cutter 25. The entire outer edge of the dial cap 15 is normally spaced inwardly of the outer peripheral edge of the saw-toothed ring 20 so that an yarns which are moved to inactive position are almost immediately drawn into engagement with the teeth on the ring 20 by the last needle to knit. This inactive yarn then passes beneath the dial cap 15 and above the dial cam plate 16 as it is moved toward the next cutter. Thus, an inactive yarn extending from the feed finger at the station V extends beneath the dial cap 15 and above the dial cam plate 16, engages guide pins 30 and 31, which are fixed in the dial cap 15 and extend downwardly therebelow, beneath the suction nozzle 21 and to the cutter 25. This yarn withdrawn from active position at station V thus has a very long free leading end when it is cut by the cutter 25. This long free leading end is easily drawn up into the suction nozzle 21 and held until the yarn is again moved to the knitting position.

Also, withdrawn yarns at the station VI extend across the dial cam plate 16 and beneath the dial cap 15, beneath the nozzle 21, and to the yarn cutter 25 so that a re ativ y .9 s ree leadin end is te med as h y rn is cut. While the length of yarn extending from the station VII to the cutter 25 is shorter than the length of yarn extending from the station VI to the cutter 25, this yarn still extends directly beneath the suction nozzle 21 in its path of movement to the cutter 25. Thus, when the yarn withdrawn from the yarn feed station VH is cut, its free leading end is easily drawn up into and held in the suction nozzle 21.

However, a yarn withdrawn at station VIII extends directly to the cutter 25 and does not pass beneath the suction nozzle 21 so that the free leading end may not be drawn up into and held in the suction nozzle 21. When an elastic type of yarn, such as a covered or wrapped spandex yarn, is fed at station VIH, it will not be caught and held by the suction nozzle 21 because the elastic yarn immediately contracts when it is cut and the short free leading end will not be drawn up into the suction nozzle 21. When the leading free end of a withdrawn yarn is not held in the suction nozzle, it will not be properly fed to the needles when it is again moved to active position and the needles will shed the knit fabric and cause a press-oft. The yarns fed from the stations I-IV are cut by the cutter 25' and held by the suction nozzle 21' in the same manner as that described in connection with the operation of the yarns at the stations V-VIII.

In accordance with the present invention, means is provided for preventing the immediate movement of all withdrawn yarns beneath the dial cap 15 and above the dial cam plate 16 and to thereby prevent engagement by certain withdrawn yarns with the next succeeding cutter. For example, the yarns withdrawn from active position at feeding stations VIII and IV, do not engage and are not cut by the respective cutters 25, 25 but by-pass these cutters and are cut at the next succeeding cutters 25', 25. This insures that the yarns withdrawn from active position at these stations pass directly beneath the pneumatic suction nozzle immediately ahead of the cutter and the yarn will be caught and held. Also, this control apparatus and method includes means for positively clamping these withdrawn yarns at a position between the by-passed cutter and the cutter which is to sever the yarn. This clamping means is in the form of a mechanical clamp which is operated in timed relationship to the yarn changing operation and holds intermediate portions of the yarns until their free leading ends have been drawn up into the corresponding suction nozzle.

The yarn control means is carried by the dial cap 15 and is engageable by yarns withdrawn from active positions atyarn feed stations VlII and IV and in advance of each of the cutters 25, 25' for preventing the withdrawn yarns from engaging the respective cutters and for directing the yarns into engagement with the next cutters. Thus, the yarn withdrawn from action at station VIII is cut at the cutter 25' and is held by the suction nozzle 21' while the yarn withdrawn from action at station IV is cut at the cutter 25 and is held by the suction nozzle 21. The yarn control means is illustrated as a pair of diametrically opposed flanges 40, 40' which extend outwardly over the toothed ring 20 and prevent the yarns from immediately engaging the toothed ring 20 so they are not brought into engagement with the correspondnig cutters 25, 25.

As sh'own in FIGS. 3 and 4, the lower ends of the respective cutters 25, 25' extend downwardly and pass through suitable openings 41 and 41 in the respective flanges 40, 40'. Immediately adjacent the flanges 40, 40', the upper portions of the dial cap 15 are cut away to form a pair of respective step-down shelves 42, 42 and over which certain of the yarns are guided, in a manner to be presently described.

The clamping means is best illustrated in FIG. 2 and is illustrated as diametrically opposed mechanical clamping devices, broadly indicated at 50, 50 in FIG. 1. The clamping devices 50, 51 are identical and only the clamping device 50 will b des ri ed n d a l i h ike ret e ss characters being applied to like parts of the clamp 50', with the prime notation added.

As shown in FIG. 2, the clamping device 50 includes an enlarged lower clamping pad or foot 51 having a reduced portion extending up inside of a tubular housing 52. The lower end of the tubular housing 52 is provided with a ring support 53 which is suitably secured to the tubular housing 52 and fixed on the upper surface of the dial cap 15. A portion of the support ring 53 extends out over the stepdown shelf 42 and a semi-circular cut-out is provided in the cap for the lower end of the clamping foot 51, so that it may move downwardly into clamping engagement with the upper surface of the shelf 42. A stem portion 54 extends upwardly from the clamping foot 51 and through a ring 55 fixed in the upper end of the tubular housing 52. The upper end of the stern portion 54 is threaded to adjustably support one end of a control arm 56 which is held in adjusted position by a lock nut 57. A compression spring 60 surrounds the stem portion 54 in the tubular housing 52 and normally urges the clamping foot 51 downwardly into clamping engagement with the upper surface of the shelf 42'.

Suitable control means is provided for at times lifting the clamping plunger 51 above the surface of the shelf 42 to receive a yarn therebetween. In the present instance, the yarn feed finger 13 at the yarn feed station VII is raised to engage the outer free end of the control arm 56 and lift the same upwardly against the pressure of the spring 60 to thereby raise the clamping foot 51. When the yarn feed finger 13 is lowered, the compression spring 60 resiliently urges the clamping foot 51 downwardly against the upper surface of the shelf 42 to clamp any yarns passing across the shelf 42.

METHOD OF OPERATION In accordance with the present invention, the yarn ends moved to inactive position at certain feeding stations to withdraw the yarns from the needles by-pass and are not cut by the next succeeding cutter but are cut by the next cutter which is positioned more than half of the distance around the needle circle from the station at which the yarns are withdrawn from action. The feed finger 12 at station 1V is illustrated as feeding an elastic yarn E, which is at times used when knitting panty hose blanks and the like. The elastic yarn E is usually incorporated in the top portion of the panty hose blank which is to form the waistband of the garment. While the cutting and clamping of the yarn E fed at station IV is described, it is to be understood that the yarn E fed at station VIII is cut and clamped in the same manner.

Upon completion of the required length of fabric to form the elastic waistband, the yarn feed finger 12 at station IV is raised from the active lowermost position to the raised upper position, as shown in FIGS. 3. The last active needle to knit immediately draws this yarn down into engagement with the flange 40 to prevent its engagement with the teeth on the toothed ring 20, rotating in the same direction and at the same speed as the needles N. As the last active needle moves in a counterclockwise direction, the yarn E is drawn across and in engagement with the flange 40 (FIG. 3) and engages a portion of the cutter 25 well above the cutting edge. The elastic yarn E is then drawn across the shelf 42, and beneath the clamping foot 51, which is then held in a raised position by upward movement of the yarn feed finger 13 at the station VII. After passing beneath the clamping foot 51, the yarn E is then drawn downwardly and passes beneath the dial cap 15 (FIG. 4) and is carried around beneath the flange 40 until it is engaged and severed by the cutter 25. As the yarn begins to move beneath the flange 40, the finger 13 at the station VII is lowered so that the clamping foot 51 moves down and clamps the elastic yarn E against the shelf 42', just prior to the time that the elastic yarn E is severed by the cutter 25.

When the yarn E is cut, the free leading end thereof starts to contract and is drawn upwardly into the nozzle 21 by the suction current where it is held until this yarn is again moved to the active position, as shown in FIG. 4. The clamping foot 51 remains in clamping engagement with the elastic yarn E until after the leading free end is drawn up into the nozzle 21, after which the clamping foot is then raised.

The yarns withdrawn from active position at the yarn feed stations II and III are drawn beneath the dial cap 15 and pass above the dial cam plate 16 to pass beneath the flange 40 so that they pass directly beneath the nozzle 21 before they are engaged and cut by the cutter 25'. The free leading ends of these yarns are drawn up into the suction nozzle 21' and held therein until the corresponding yarn feed fingers are again lowered to the active position.

The yarn withdrawn from active position at the station V is not cut by the cutter 25 but is drawn downwardly beneath the shelf 42 (FIG. 3) and above the dial cam plate 16 to engage the guide pins 30, 31 so that it extends beneath the suction nozzle 21 as it is moved around toward the cutter 25, as shown in FIG. 4. When this yarn reaches the cutter 25, its free leading end is drawn up into the suction nozzle 21 and held therein until it is again moved to active position.

Thus, in accordance with the present invention, the by-passing of certain yarns to cause them to miss the next succeeding suction holding device and cutter insures that these yarns will pass directly beneath a suction holding nozzle and will have sufficiently long free leading ends that they will be caught and held as soon as they are severed. Also, the use of the clamping members insures that elastic yarns are sufiiciently held that they will be caught and held by the suction holding nozzles.

In the drawings and specification, there has been set forth a preferred embodiment of the invention, and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation.

What is claimed is:

1. In a multi-feed circular hosiery knitting machine having a rotating circle of needles, a stationary dial cap supported inside of said circle of needles, a stationary dial plate supported beneath said dial cap and having an outer peripheral portion spaced therebeneath, a toothed ring mounted for rotation on said dial plate and spaced beneath said dial cap, a plurality of spaced apart yarn feeding stations positioned around said needle circle, and yarn feed fingers at each station and being movable between active and inactive positions to introduce and withdraw yarns from said needles, the combination therewith of control means for cutting and holding withdrawn elastic and inelastic yarns, said control means comprising (a) a pair of cutters on said stationary dial cap and in diametrically opposed relationship, said cutters cooperating with said toothed ring to sever yarns brought into contact with said cutters by said ring,

(b) pneumatic yarn holding means positioned in advance of each of said cutters for holding the free leading ends of inactive yarns when severed by the next succeeding cutter,

(c) a stepdown shelf formed along the upper surface of said stationary dial cap and being positioned in advance of one of said pneumatic yarn holding means,

(d) a yarn control flange positioned in advance of said step-down shelf and extending outwardly from said stationary dial cap and over said toothed ring, said flange being engaged by and preventing an elastic yarn withdrawn from active position at one feed station in advance of one of said cutters from engaging said one cutter, said flange directing the elastic yarn above the corresponding step-down shelf, beneath said one pneumatic yarn holding means and into engagement with the next of said cutters, said flange also preventing an inelastic yarn withdrawn from active position at another feed station in advance of each of said cutters from engaging the said one cutter and directing the inelastic yarn along the space between said dial plate and said dial cap to maintain the inelastic yarn separated from the elastic yarn directed along said step-down shelf, and

(e) a clamping foot supported for vertical movement into and out of engagement with said step-down shelf for clamping the elastic yarn withdrawn from knitting action and guided over said step-down shelf and prior to being cut by said next cutter.

2. In an apparatus according to claim 1 including resilient means normally urging said clamping foot downwardly into engagement with said shelf.

3. In an apparatus according to claim 2 including a control arm operatively connected at one end to said clamping foot and having a free end overlying one yarn feed finger at an adjacent yarn feeding station whereby said control arm is engaged and raised when said one yarn feed finger is raised to inactive position.

4. A method of controlling the cutting and holding of elastic and inelastic yarn ends withdrawn from active knitting position in a multi-feed circular hosiery knitting machine including a rotating circle of needles, a stationary dial cap supported inside of said circle of needles, a stationary dial plate having an outer portion spaced below said dial cap, a toothed ring supported for rotation beneath said dial cap, a plurality of spaced-apart yarn feeding stations positioned around said needle circle, yarn feed fingers at each station and being movable between active and inactive positions to introduce and Withdraw yarns from said needles, a pair of cutters supported on said stationary dial cap and in diametrically opposed relationship at opposite sides thereof, and pneumatic yarn holding means positioned in advance of each of said cutters for holding the free leading end of an inactive yarn when it is severed by the next succeeding cutter, an elastic 8 yarn being fed at at least one of said feeding stations in advance of one of said cutters, said method comprising the steps of (a) moving to inactive position the inelastic yarns at certain feeding stations, directing the same beneath the next pneumatic yarn holding means, and cutting the removed yarn at the next succeeding cutter, (b) moving to inactive position the inelastic yarn at one feeding station and directing the removed yarn past the next succeeding cutter, along the spaced below said dial cap and beneath the pneumatic yarn holding means at the opposite side of the dial cap, and cutting the removed yarn at the cutter at the opposite side of the dial cap, and (c) moving to inactive position the elastic yarn at at least one yarn feeding station and preventing the same from engaging the next successive cutter and while directing this withdrawn elastic yarn above said dial cap, and clamping the same against the upper surface of said dial cap prior to the elastic yarn being cut by the next successive cutter.

References Cited UNITED STATES PATENTS ROBERT R. MACKEY, Primary Examiner US. Cl. X.R. 

